A plotly dash app where I want to have a dynamic number of text boxes and access their values from a callback when a button is pushed.

dash-dynamic-fiddling.py

import dash
from dash.dependencies import Input, Output, Event, State
import dash_core_components as dcc
import dash_html_components as html


app = dash.Dash()
app.config.supress_callback_exceptions = True
app.css.append_css({'external_url': 'https://codepen.io/chriddyp/pen/bWLwgP.css'})


## function to generate input widgets
## num_slider is a slider from 1-4, initialized to 1
## text_boxes is a div placeholder for on-the-fly generated text fields
## run_button is a button
def generate_inputs():

    num_slider = [html.Label(html.Strong('select number')),
                  dcc.Slider(id='num', min=1, max=4, value=1,
                             marks={i: i for i in range(5)})]
    
    text_boxes = [html.Label(html.Strong('text inputs')),
                  html.Div(id='boxes')]

    run_button = [html.Label(html.Strong('ready?')),
                  html.Button('run!', id='run', n_clicks=0)]

    input_list = [num_slider, text_boxes, run_button]
    widgets = list()    
    for sublist in input_list:
        sublist.append(html.H1(''))
        for item in sublist:
            widgets.append(item)

    return widgets


## generate_input and an empty ghost div where I can send results
app.layout = html.Div([
    html.H2('app'),
    html.Div(generate_inputs(),
             style={'float': 'left', 'width': '20%', 'padding': '0 0 50px 0'}),
    html.Div(id='lookups',
              style={'float': 'right', 'width': '75%'})
    ])


## when the number of the slider changes, run this
## for this demo, not doing this as I've hardcoded id='a'. In practice
## I'd have the id be str(i) or something.
@app.callback(
    Output('boxes', 'children'),
    [Input('num', 'value')])
def ins_generate(n):
    return [html.Div(
        dcc.Input(id='a',
                  placeholder='a thing', value='thing',
                  size=40, type='text')) for i in range(n)]


## when the button is clicked, access our on-the-fly field
@app.callback(
     Output('lookups', 'children'),
    [Input('run', 'n_clicks')],
    [State('a', 'value')])
def create_lookup(n_clicks, val):
    print(val)


if __name__ == '__main__':
    app.run_server(debug=True)

Thanks, interesting post. Did not work for me though. Got "error loading dependencies".